Monitoring apparatus for monitoring the operation of single seed drills are known in various versions. Often the monitoring is carried out on a conveyor channel due to easy accessibility, such as for example in document WO 2005/096799 A1 or WO 2005/096798 A1.
Monitoring devices are used among others to control and regulate as well as check the proper operation of sowing devices. There is the requirement that the monitoring responds promptly and works properly and simply. Furthermore, the monitoring apparatus should work as economically and as free of maintenance as possible.
DE 10 2011 001 949 A1 describes a sowing heart monitoring apparatus for a sowing heart, pulses generated by a line scanning camera being evaluated by an evaluation unit in order to evaluate the occupancy of each sowing hole immediately after detection, therefore on-line.